Pressure casting machine



Marc'h 29, 1933. N. LES-naa` ET AL 2,112,343

` PRESSURE CASTING MACHINE Filed July :5, 1935 2 sheets-sheet 1 Y INVENTOR fa' aw feeff fw mikem/17( (655er H7 @M/uk v 9 ATTORNE 6.

March 29, 1938. N LESTER ET AL 2,112,343

PRESSURE CASTING MACHIN.

Filed July 3, 1935 2 Sheets-Sheet 2 oJ I A. MM

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Patented Mar. 29, 1938 s PATENT OFFICE 2,112,343 d vPRESSUREcastano. MACHINE Nathan Lester, Cleveland Heights, Ohio, andWil- `liam M. Lester, Leominster, Mass., assignors to Lester Engineering Company, Cleveland, Ohio, a corporation of Ohio Application Julya', 1935, serial Navzassa 1c claims. (ci. .c2-ss) The present invention relates to an apparatus l Now referring more particularly to Fig. 1, the for casting metal under relatively high pressure pressure casting 1machine shown therein consists wherein a charge of metal is forced from a presof a supporting base I carrying the horizontal tie sure chamber into a permanent mold cavity derods 2, the end tie plate 3and the upper tie rods fined by a pair of separable die blocks. l (only one each of the tie rods 2 and l being The general object andnature of theinvention shown). A die plate 5 is carried by the right is to transfer a measured charge of metal, suflihand end of the tie rods 2 and l, or upon the cient to completely fill the mold cavity and gate, end opposite to that of the tie plate 3. A movable from a melting pot, to a pressure chamber, and die plate 6 is also carried upon the intermediate to eject a quantity of metal therefrom into the portion of the tie rods 2 and `I. The die plates 5 mold cavity without exposing such metal to the and 6 are adapted to carry the die blocks 1 and atmosphere and without entrapping any air or 8 respectively, whose opposed faces define a mold air bubbles in the casting charge. cavity 9. v

A further object of the invention is to provide Toggle link mechanism indicated generally-by means for ejectlng `surplus metal or solidified the numeral I0, together with the hydraulic acgslugs from the charging chutethrough which tuatlng cylinder II, connects the end tie plate 3 the molten metal isv transferred into thev pressure to the movable die plate 6. The die plate 6 is chamber. Another object of the invention is to carried upon the movable Plate l2 by means 0f provide a measuring plunger adapted to vary the a screw jack mechanism I3 whereby the position volume capacity of the pressure chamber and to of the die plate 6 with respect to the movablemaintain the casting charge in a compact mass plate I2 may be variably regulated. The last until it is in position to enter4 the mold cavity. described mechanism for actuating the die plate 6 A further object is to provide means for autois not claimed as novel in the present invention, maticallyregulating the position and movement since it is embodied in the subject matter and of such measuring plunger. explained in detail in the copending application Still another object of the invention is to proof William M. Lester, Serial No. 5,438, flied Februvide a melting pot and furnace structure which ary 7. 1935- can be quickly and` easily removed and replaced A pressure Casting Chamber 0r Cylinder l5 1S from the casting machine assembly. Additional mounted in the die plate 5. A pressure plunger objects and advantages shall become apparent I6 enters the right hand end of the casting cylduring the following description. o lnder I5 and is connected to the piston rod I1 To the accomplishment of the foregoing and leading to the hydraulic pressure cylinder I8. related ends, said invention, then, consists of Flexible connections I9 and 20 communicate with the means hereinafter fully described and parthe interior of the pressure plunger I6, which yis ticularly pointed out in the claims. hollow and are for the purpose of circulating a The annexed drawings and the following decooling medium Such as water or oil within scription set forth in detail certain mechanism the interior of the plunger I6. The hydraulic embodying the invention, .such disclosed means cylinder I8 is mounted upon the base I by means constituting, however, but one ofk various meof a supporting bracket 2|. chanical forms in which the principle of the in- A charging Chute 24 leads from the pressure vention may be used. 1 casting cylinder I5 to the metal melting pot 26.

In said annexed drawings:-. The melting pot 26 is in turn mounted in a. heating Fig. 1 is an elevational view in section of the furnace `structure 21. The melting pot 26, the assembly of the machine embodying the principle heating furnace 21 and its housing 2B is mounted of our invention; Fig. 2 is an enlarged sectional upon the supporting rollers 29 whereby the meltview ofthe charging chute and pressure chaming pot and furnace can be rolled laterally, that ber taken upon a plane normal to that of Fig. 1 is, in a direction normal to the plane of Fig.v 1, and substantially along the -line v2--2 thereof; from under the casting machine, merely by re- Fig. 3 illustrates an alternative form of construcmoving the charging chute 24. In this manner, tion for the parts shown in Fig. 2; Fig. 4 is an a melting pot and furnace which needs repair enlarged fragmentary sectional view taken upon may be very easily removed and replaced in posi- `a plane normal to that of Fig. 1 and substantially tion with respect to the casting machine, or the melting pot and furnace containing a different composition of metal may be conveniently substituted when desired.

UNITED STATE along the line 4-4 thereof, showing the connection betweenl the measuring plunger shaft and the auxiliary resistance shaft.

y cylinder Il. Suitable studs 33, Il fasten the cap 22 to the face of the charging chute portion Il.

The upper end of the chagiugchute' pamage 2l intersects and' communicates with the interior ol the casting cylinder II, as indicated at Il.

Fior-the purposesvof convenient fabrication, and machine practice, the rectangular cylinder housing 3i may be made into two-.pieces Joined together along the lparting line Il in the same plane as the arial center of the charging chute passage.

A vacuum passage leads from the upper end of the charging chute passage 2l -to the port 21 which in turn is connected to the vacuum conduit 38. The vacuum conduit 3l leads to a.

vacuum pump or motorV (not shown). l`The vacuum passage 33 is of cylindrical form and 'a plunger or piston il is mounted therein. The upper end of the piston 39 carries a gear rack III adapted to be engaged by the gear segment 4I on the end of the lever 42. Thevlever l2 is pivoted at the point 43 and carried by the housing Il which in turn is threadably mounted as at` to the upper end of the charging chute 24. The housing Il alsoserves as a guide for the reciprocal movement of the enlarged upper end 46 of the piston II. A connecting rod 41 connects the outer end of the lever 42 to the movable tie',`

plate I2. Thus movement of the die plate t and of the movable plate I2 operates `to oscillate the lever 42 about its 'pivot point v and to thereby raise and lower the piston 39. `When the piston 39 reaches its uppermost position, fas shown in Fig. 2, the vacuum passage port 31- will be opened andthe vacuum placed in communication withthe charging chute passage and the interior of the casting cylinder I5.- On the, downward movement of the piston 4*39,the vacuum passage port l1 will be closed and? continued downward movement will extend'the piston 38 into the vacuum..v

passage ,3Q and the upper end of the charging `chute passage 2B-whereby excess metal which might havefrozen out in the upper end of the passagejand in the passage 36 will be forcibly ejected and dropped back into the melting pot 26.

For the Vpurpose of conveniently removing and replacing the charging chute, the alternative form of construction as shown in Fig. 3 may be employed. In Fig. 3,'the charging chute ismade in the form of a separableelement 24' .which threadably engages the housing as at Il. A hexagonal portion 49 on the outer surface of-the charging I chute 24' is for the reception of a wrench whereby the chute 24 may be conveniently screwed on or unscrewed from the housing 3U' Y Directingl attention to Fig. I, a measuring plunger B0 extends through the die blocks 1 and l and is adapted to enter the left hand or discharge end of thecasting cylinder I5. The end oi.' themeasuring plunger 50 and the end -of the pressure plunger Il thus define end walls in the pressure cylinder I5. The left hand or outer end II of the measuring plunger 50 is journalled in the movable die plate 6 and has a gear rack which meshes with thegear teeth on the transverse shaft 52. The shaft 52, as will be best seen in Fig. l, is lournalled in a recess in the die plate 6 and held therein by means of the cap screw 53. The lower end of the guasta transverse shaft l2 meshes with a gear rack II on the end of the auxiliary shaft I4. Theauxiliary shaft Il is carried by downwardly projectingbosses Il and Il extending from the die plate i and themovable plate I2 respectively.

' It will thus be seen that the measuring plunger shaft II and the auxiliary shaft Il are so connected'by the cross shaft l2 that movement of either one in a given direction will be transmitted into movement of the other in an opposite direction. Forexample, when the measuring plunger Il and its shaft il are moved in a left hand direction with respect to Fig. 1,- the cross connecting .shaft I2 will be rotated in such a direction'. as to transmit the left-hand movement of the shaft II into a right-hand movement of the shaft M.

f The left hand end of the shaft I4 is connected to the,adJustable, threaded spindle or shaft Il' hy-means of the sleeve `Il and a friction pack-4 ing gland composed of the bushing I2 and the friction packing material Il.y 'Ihe shaft l0 threadably engages an internally threaded sleeve I4, the latter being fixed to the base I. The outer end oi' the shaft il is squared as at Il for the reception of a suitable rotating tool or wrench whereby 4the position of the shaft l0 may be adiustably regulated with respect to the fixed base I.

The operation'` of the automatic measuring. plunger Il4 and' its i above describedf connectingy mechanismlisas'follov'o's:-` l l when the vcasting cynnderunis nues with molten metal by -theaction of the vvacuum vthrough the passage irland through the charging chute passage 2l, the pressure -plunger Il is then moved in a left hand or dischargingv direction. Compression of the metal charge in the 4ward movement of the measuring plunger 80 with respect to the lcasting cylinder Il is resisted, but the pressure exerted ybythe pressure plunger Il is sulcientto overcome suchresistance until thev shoulder on the measuring plunger Il abuts against the face of the die plate 6. At

this point the right hand-.end of the measuring plunger. cleare'dithe sprue opening BI'to the'moldcavity 9, as indicated by the dotted line 08 and, further movement of the pressure plunger Ilforces the metal charge into the mold cavity 9. At the next stage of operations, when the movable die plate 6 is moved in a left hand direction in order to open the die blocks 1 and 8. such movement will tend to rotate the cross connecting shaft l2 inra counterclockwise direc-- tion as viewed in Fig; 1; but since the shoulder I6 abuts against the face of the die plate i, such counterclockwise rotation will not be possible and the shaft 52 will therefore become locked, with,the result that the position of the shaft Il' with respect to the movable die plate l is also locked. Hence left hand movement of the ydie -,plate I, due to the locking of the cross shaft 52 will be transmitted into left hand movement of the shaft 54, into the space 69 between its left hand end and the end of the threaded shaft 25, inder il resulting inagreater' volume-'capacityof the latter.

9,119,848 i A p having a meltingpot. 'a pressure'chalnber. for receiving and iluid metal under pressure,'and a pressure connectedto said4 chamber for transferring jiluid metal thereinto` ll. On closing movement of the die blocks 1 and l, or on right-hand movement of the die plate 0, the resistance exerted by the Afriction packing "u will tend to hold the shaft u in place with `v Fig. i 4 i i `In order to variably regulate the initial start- 4 and thereby `move plunger Il in a right hand direction.` and back the resultthat the cross shaft will be rotated ina clockwise direction with respectto Pig. l'.

the shaft Il and measuring into-its original starting position,v asf'shown ing position of the measuring plunger Il, and

. incidentally, of course, to vary'the volume capacity of the cylinder Il, the position ofthe threadvaried. Thus, if the threaded shaft IU is moved edshaft I0 withrpecttothenxedbase I is in a left hand-direction. such movement will be transmitted through the shaft Il. the cross 'shaft l2 to the :measuring plunger Y, withf the result that the latter will move further into the `castingcylinder Il and thereby reduce the volumecapacity of `the latter. Gouversely,l right hand'` movement of the threaded shaft lwill move the measuring plimger llin aleft `hand direction or outwardly with respect to the' cyl- In4 this manner, the, metal cast- `ling charge `received and delivered bythe casting cylinder I 5 may be adlustably varied fas frei.- quired and demanded.

It should be noted that the lower end of the charging chute 24 extends below4 thelevel 1I of atmospheric contact. Thus, it will'be seen that-l `the metal in the melting pot 2l. `An inert material yspread over thetop ofthe metal in the melting pot 2l serves to seal -the metal from the above described pressurev casting machine `accomplishes the functions and results of receiving a measured quantity of molten metal from the `melting pot without exposing the metal to oxidation by contact with the atmosphere, transfers such measured charge of metal `in la Vcom- 'pact body to the opening into the mold cavity.

and also elects any solidified or frozen out slug from thefeed into the casting cylinder back into the melting pot. Theabove described machine also effects a convenient means for adlustably varying the capacity of the casting cyll passage 25, the top of the vmelting potfi" could I be hermetically sealed and a'greater thangatmosinder, and correspondingly, the amount of the measured metal charge.

pheric pressure introduced therein whereby the molten metal would be forced up through the charging chute 2l and' into the interior ofthe pressure casting cylinder i5.

. Other modes of applying the principle of our invention may beV employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the 'means stated by any of `the following claims or the equivalent of such stated meansbe employed.

We therefore particularly point `out and' distinctlyclaim as our inventionz 1. vIn a pressure casting machine oi' the type from the melting pot', the combination of means for electing excess metal from said passage back luto #sid Bie-111118 90h r l 2.,In a pressure. castingmachineof the'type having a melting pot, ia' pressure vchamber' for receiving and discharging fluid metal-under pres- Vsure, and a pressure 4passage connected Lto. said chamber for transferring fluid metall thereinto` from the melting pot. the combination of means for openingand closing saidv passage and also. vfor electing excess mctalfromsaidpassage back into said melting i lmapressurecasting ceiving land discharging fluid under pressure. and a vacuum-passage'connectedto .said

the meltingpot, the combination of means for measuring thel amount of metal discharged from said chamber, and 4means for electing excess metal from said passage back into said melting receiving and dischargingv uid'metal under ,pres- Asure.,an,i a passage connectedto said' chamber for drawing iiuid thereinto from said/ melting pot, the combination .ofmeans'movable ofthe-tm; having ameltlng potpapressure 'reim berforre.

4,'1na pressure casting machine of the type having'a melting pot.' a pressure for Vwenn; the interior orma enamberfrer redsun:

the discharge of metal `therefroinfand also for lvarying the volume capacityof lsaid chamber,

and means for, electing sure, .and a vacuum passage' connected -to said chamber forl drawing fluid thereinto lfrom said melting pot, the combination of means movable withl the interior of said chamber for resisting` the discharge of metal therefrom and also forl v excessmetal fromsaidf j passage backiniaosaid'meltingpot-` 4 5.'In a pressure'` casting Au ia'chine of 'the type:` having a meltingpot, aj pressure chamber for re' ce'iving and discharging fluid vmetal under 'presvarying thel volume `capacity of said chamber,

and means for opening and closing saidpassage and also for electing excess metalfrom said pas# sage back into said melting pot.

, 6. In a pressure casting machine of the type having a melting pot. separable die blocks vdefining a mold cavity, means for openingand closing said blocks, and a pressure cylinderand plunger therein for discharging fluid metal .into said cavity, the combination'of a secondphmger carried by one of said blocksy and movable, into and out of the discharge end of said. cylinder, the pressure generated by said mst-named plunger being ,adapted to movey said second plunger outward with respect to said cylinder,

` the closing movement of said blocks being adaptlf vedto move said second plunger inwardly with lrespect to said cylinder,I and means for-adjustably regulating the extent of such inwardmovement. l

"1. In al pressure casting machine of the type having a melting pot, separable die blocks defining a' mold cavity, means foropening and closing said blocks, anda pressure cylinder and plunger therein for discharging fluid metal into said cavity, the combination of a second plunger carried by one of said blocksand movable into and out of the discharge end of said cylinder,

l means for stopping the outward movement of said secondplunger at a point where dts end has cleared the entrance lto said cavity, the pressure generated by said mst-named plunger being adapted to move said second plunger outwardly with respect to said cylinder, the closing movement of said blocks being adapted to move said second plunger inwardly with respect to said cylinder, and meansfor adjustably regulating the extent of such inward movement.

8. In apressure casting machine of thetype having a melting pot, separable die blocks dening a mold cavity, means for opening and closing said blocks, and a pressure, cylinder and plunger therein for discharging fluid metal into said cavity, the combination of a second plunger carried by one of said blocks and movable into and out of the discharge end of said cylinder, means for stopping the outward movement of said second plunger at a point where its end has cleared the entrance of said cavity, means for resisting the outward movement 'of said second plunger with respect to said cylinder, the pressure generated by said first-named plunger being adapted to move saidsecond plunger outwardly with respect to said cylinder, the closing movement of said blocks being adapted to move said second plunger inwardly with respect to said cylinder,

` and means for adjustably regulating the extent of such inward movement.

9. In a pressure casting machine of the type .having a melting pot, a pressure cylinder and a plunger therein, and a charging chute communicatingv between said pot and said cylinder, the combination of a vacuum passage terminating at apoint in alignment with the upper end of said chute and adjacent the juncture of said chutev and of said cylinder, and means for ejecting excess metal from said chute back into said melting pot.

10. In a pressure casting machine of the type having a melting pot, a pressure cylinder and a plunger therein, and a charging chute communicating between said pot and said cylinder, the combination of a vacuum passage terminating at l the juncture oi' said chute and of said cylinder,

and a piston movable in said passage for opening and closing the latter, said piston being also -adapted to eject excess metal from said chute back into said melting pct.

1l. In a pressure casting machine of the type having a melting pot, separable die blocks defining a mold cavity, means for opening and closing said blocks, a melting pot, a pressure cylinder and a plunger therein, and a. charging chute communicating between said pot and said cylinder, the combination of a vacuum passage terminating adjacent the juncture of said chute and of `said cylinder, a piston movable in said passage for opening and closing the latter, said piston being also adapted to eject excess metal from said chute back into said melting pot, and means operable by .the movement of said die blocks for actuating said piston.

l2. In ya pressure casting machine of the type having a melting pot, separable die blocks dening a mold cavity, means for opening and closing said die blocks, a pressure cylinder and plunger therein for discharging fluid metal into said cavity, and a charging chute communicating between said pot and said cylinder, the combination of a sec-end plunger carried-by one of said blocks and movable into and out of the discharge end of said cylinder, the pressure generated by said first-named plunger being adapted to move said second plunger outwardly with respect to said cylinder, and the closing movement of said blocks being adapted to move said second plunger inwardly with respect to said cylinder, a melting pot, a vacuum passage terminating adjacent 'the juncture of said chute and of said cylinder, and means for ejecting excess metal from said chute back into said melting pot.

13. In a pressure casting machine of the type having a melting pot, separable die blocks defining a mold cavity, means for opening and closing said blocks, a melting pot, a pressure cylinder and a plunger therein, and a charging chute communicating between said melting pot and said cylinder, the combination of a secondy plunger carried by one of said blocks and movable into and out of the discharge end vof said cylinder, the pressure generated by said first-named plunger being adapted to move said second plunger outwardly with respect to said cylinder,and the closing movement of said blocks being adapted to move said second plunger at a point where its end has cleared the entrance to said cavity, means for resisting the outward movement of said second plunger with respect to said cylinder, means for adjustably regulating the extent of such inward movement, a vacuum passage terminating adjacent the juncture of said chute and of said cylinder, and a piston movable Lin said passage for opening and closingl the latter, said pistonV being also adapted to eject excess metal from said chute back into said melting pot.

4li. In a pressure casting machine of the type having separable die blocks defining a mold cavity, means for opening and closing said blocks, a supporting base, and a pressure cylinder i'or receiving and discharging iiuid metal into said cavity, thecombination of a plunger movable into and out of the discharge end of said cylinder for varying the volume capacity thereof, the

outer end of said plunger being slidably supported by one of said blocks, a shaft parallel to said plunger, a second shaft having its axis normal to said plunger and said first-named shaft, rack and gear means connecting said secondnamed shaft to said plunger and said rst-narned shaft whereby movement in one direction of said plunger istransmitted to movement in an opposite direction of said rst-named shaft, and friction detent means slidably connecting said firstnamed shaft to said supporting base, and means for adjustably regulating the position of said friction detent means.

15, In a pressure casting machine of the class wherein iluid metal is fed through one of a pair of separable die blocks from a pressure chamber carried bysaid one of the pair of die blocks, and a plunger in said chamber for discharging fluid metal from said chamber under pressure, the combination of means independent of said plunger and carried by the other of said pair of die blocks for varying the volume capacity of said chamber.

t 16. In a, pressure casting machine of the class wherein uid metal is fed through one of a pair of separable die blocks from a pressure chamber carried by said one of the pair of die blocks, and a` plunger in said chamber for discharging uid metal frcmy said chamber under pressure, the combination of means independent of said Yplunger and movable Within the interior of said chamber for resisting the discharge of metal therefrom and also for varying the volume capacity of said chamber, said means being carried by the other of said pair of 'die blocks.

NATHAN LESTER. WILLIAM M. LESTER. 

